Media captionBarclays will raise £5.8bn through a new share issue, to shore up its finances

Barclays was widely regarded as one of the UK's strongest banks.

So it is remarkable that its regulator, the Bank of England's Prudential Regulation Authority, has ruled that it needs to fill a hole in its capital resources - the funds that it puts aside as a protection for depositors and creditors - of £12.8bn by the middle of next year.

It is the only one of the UK's biggest stock-market banks that has been set such a challenge.

Barclays is meeting it by asking its shareholders to provide almost £6bn of new equity, by selling bonds to raise a further £2bn and by shrinking its balance sheet - in essence the credit it provides - by up to £80bn (it is doing this largely by reducing investment banking activity in derivatives and financing of securities deals).

Barclays chief executive Anthony Jenkins, speaking to me on the Today programme, insisted that there would be no reduction in the supply of vital loans to small businesses and households.

Barclays also disclosed that it expects to incur a further £2bn of losses from paying compensation to people missold PPI insurance and small businesses missold so-called financial products called swaps.